1. Technical Field
The present invention relates generally to fluid jet particle cleaners. More particularly, the present invention relates to a non-contact fluid jet particle cleaner and method that shape fluid vortices to more efficiently remove particles.
2. Related Art
Fluid jet particle cleaners are commonly used to remove minute particles from products in a wide variety of industries. One illustrative industry in which these cleaners find application is the semiconductor industry. In this industry, yields and mask life in a manufacturing line are very sensitive to the presence of small particles that are less than 5 mils in diameter on the product surface. Fluid jet particle cleaners provide a low cost solution to clean the surface of a product.
FIG. 1 illustrates a conventional fluid jet particle cleaner 10 that propels a fluid 12 such as air onto a surface 14 of a product 16 to release particles therefrom, and then vacuums 18 the airstream to remove the particles. While many particles in a given diameter range are removed by cleaner 10, some of the particles escape vacuum 18 flow and fall back onto surface 14 at a different place than where they were originally. FIG. 2 illustrates streamlines for the simulated section indicated in FIG. 1. The streamlines indicate the path a very small particle with low inertia may follow if suspended in fluid 12. The closer the streamlines are to one another, the stronger the vortex. As shown in FIG. 2, escaping particles dislodged form surface 14 by fluid 12 are able to bypass vacuum 18 flow because they are accelerated quickly to high speeds with a large horizontal velocity component by a single air vortex 20 created by the strong fluid jet 12. The elongated bottom of air vortex 20 that contacts surface 14 illustrates this phenomenon. Unfortunately, one or just a few of such escaping particles can have a direct impact on yield and screening process performance in the semiconductor industry.
Another approach implements full contact equipment such as tacky rollers to collect particles. However, this approach is not always applicable to all situations and adds processing cost, product handling steps, and sometimes transfers chemicals to the surface being cleaned.
In view of the foregoing, there is a need in the art for a non-contacting particle cleaner that addresses the problems of the related art.